22 September 2015

CIS-48 probe/marker signal

heard today on 17289.0 KHz on USB (on May 21 also, but on 17234.0 KHz there) from 1140z, this is the so-called 'CIS-48 probe/marker of channel' signal, according as defined here in radioscanner forum. The probes are sent every ~16 Sec - at least in this sample - in quite long sessions w/out any other signal during the monitored time (more than 1 hour) and consist of 4 x DPSK 50 baud modulated tones, located at 500 Hz, 1250 Hz, 1750 Hz, 2500 Hz and spaced by 750, 500 and 750 Hz, bandwidth is 2000 Hz. A short recording is available.